scholarly journals Analysis of Primary Energy Factors from Photovoltaic Systems for a Nearly Zero Energy Building (NZEB): A Case Study in Lithuania

Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4099 ◽  
Author(s):  
Rokas Tamašauskas ◽  
Jolanta Šadauskienė ◽  
Dorota Anna Krawczyk ◽  
Violeta Medelienė

Following a new climate and energy plan, the European Union (EU) gives big attention to energy savings. The overall assessment of energy saving measures is very important. Thus, it is crucial to estimate in a proper way the primary energy factor, which is used in calculations of primary energy consumption from renewable energy (RE) sources in a Nearly Zero Energy Building (NZEB). The conduced studies of the literature and national regulations showed that different methods to determine energy from photovoltaic (PV) systems are used. The aim of this paper is to evaluate the primary energy factors of energy from photovoltaics and determine the average value. To achieve this aim, the data of 30 photovoltaic systems from Lithuania were analyzed. The results show a 35% diversification in the values of non-renewable primary energy factor, depending on the PV systems’ capacities, with the average on a level of 1.038.

Proceedings ◽  
2020 ◽  
Vol 51 (1) ◽  
pp. 5
Author(s):  
Rokas Tamašauskas ◽  
Jolanta Šadauskienė ◽  
Dorota Anna Krawczyk ◽  
Violeta Medelienė

The European Commission has set the target in the Energy Efficiency Directive (EED) to reduce EU primary energy consumption in 2020 by 20%. A crucial aspect of the overall assessment of energy saving measures that affect electricity demand is the primary energy factor that is used for evaluation of primary energy consumption from renewable energy resources in a Nearly Zero Energy Building (nZEB). The analysis of the resources has revealed that energy from photovoltaics is evaluated using different methods. Therefore, this article’s aim is to investigate and evaluate the primary energy factor of energy from photovoltaics using the data of produced and consumed energy of 30 photovoltaic (PV) systems operating in Lithuania. Investigation results show that the difference of non-renewable primary energy factor between the PV systems due to capacities is 35%. In addition, the results of the studies show that the average value of the primary energy factor of PV systems in Lithuania is 1.038.


2021 ◽  
Vol 11 (9) ◽  
pp. 4141
Author(s):  
Yovko Ivanov Antonov ◽  
Per Kvols Heiselberg ◽  
Michal Zbigniew Pomianowski

Reaching environmental targets set by the European Union (EU) requires a constant renovation of the existing building stock to nearly Zero Energy Buildings (NZEB) in a cost-optimal manner. Studies show that the renovation rate of the existing building stock is more than two times less than what is necessary to reach the targets. Furthermore, the majority of performed renovations across the EU reach just a small amount of energy savings, whereas NZEB renovations are rarely achieved. This paper proposes a methodology for the evaluation of renovation measures, aiming to provide decision support related to the selection of what to renovate and to what extent. The proposed method is rooted in the well-established cost-optimal methodology, yet it suggests a pre-step to package evaluation. This is done by means of a simplified cost-effective parameter (CEP), linking cost, lifetime, and energy savings. The methodology is demonstrated using a case study building in Denmark. The results show that the CEP provides good grounds for the compilation of single actions to packages. Further developments could focus on the sensitivity of the model inputs and integration of additional evaluation parameters to cost, such as environmental, architectural, comfort, risk, etc.


2021 ◽  
Vol 312 ◽  
pp. 02005
Author(s):  
Lorenzo Belussi ◽  
Ludovico Danza ◽  
Matteo Ghellere ◽  
Italo Meroni ◽  
Francesco Salamone ◽  
...  

Since its introduction in 2010, the nearly Zero Energy Building (nZEB) concept has known a large diffusion in European countries. Albania, an aspiring candidate country to join the European Union EU, is paving the way towards its introduction by transposing EU directives in the fields of energy efficiency into the national legislation. Most of the national building stock includes buildings with low thermal and energy performance but with high refurbishment potential, too. The country can become an important contributor in the EU decarbonization strategy due to the high percentage of electricity produced by hydropower stations, making it one of the least carbon-intensity countries in the electricity production point of view. The article focuses on the evaluation of the energy performance of an existing school located in Tirana and the potentialities to reach the nZEB target, analysing both the suitable technological solutions and the energy market situation. The Primary Energy Factors PEF for the local electricity market are estimated referring to statistical data and in comparison, with neighbouring countries, Italy and Greece, in order to investigate the potential of the achievement of the nZEB target in Albania.


Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2165
Author(s):  
Sam Hamels

The European Union strives for sharp reductions in both CO2 emissions as well as primary energy use. Electricity consuming technologies are becoming increasingly important in this context, due to the ongoing electrification of transport and heating services. To correctly evaluate these technologies, conversion factors are needed—namely CO2 intensities and primary energy factors (PEFs). However, this evaluation is hindered by the unavailability of a high-quality database of conversion factor values. Ideally, such a database has a broad geographical scope, a high temporal resolution and considers cross-country exchanges of electricity as well as future evolutions in the electricity mix. In this paper, a state-of-the-art unit commitment economic dispatch model of the European electricity system is developed and a flow-tracing technique is innovatively applied to future scenarios (2025–2040)—to generate such a database and make it publicly available. Important dynamics are revealed, including an overall decrease in conversion factor values as well as considerable temporal variability at both the seasonal and hourly level. Furthermore, the importance of taking into account imports and carefully considering the calculation methodology for PEFs are both confirmed. Future estimates of the CO2 emissions and primary energy use associated with individual electrical loads can be meaningfully improved by taking into account these dynamics.


Energies ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 895 ◽  
Author(s):  
Ilaria Ballarini ◽  
Giovanna De Luca ◽  
Argun Paragamyan ◽  
Anna Pellegrino ◽  
Vincenzo Corrado

Directive 2010/31/EU promotes the refurbishment of existing buildings to change them into nearly zero-energy buildings (nZEBs). Within this framework, it is of crucial importance to guarantee the best trade-off between energy performance and indoor environmental quality (IEQ). The implications of a global refurbishment scenario on thermal and visual comfort are assessed in this paper pertaining to an existing office building. The retrofit actions applied to achieve the nZEB target consist of a combination of envelope and technical building systems refurbishment measures, involving both HVAC and lighting. Energy and comfort calculations were carried out through dynamic simulation using Energy Plus and DIVA, for the thermal and visual performance assessments, respectively. The results point out that energy retrofit actions on the building envelope would lead to significant improvements in the thermal performance, regarding both energy savings (−37% of the annual primary energy for heating) and thermal comfort. However, a daylighting reduction would occur with a consequent higher electricity demand for lighting (36%). The research presents a detailed approach applicable to further analyses aimed at optimizing the energy efficiency measures in order to reduce the imbalance between visual and thermal comfort and to ensure the best performance in both domains.


Proceedings ◽  
2020 ◽  
Vol 51 (1) ◽  
pp. 4
Author(s):  
Rokas Tamašauskas ◽  
Jolanta Šadauskienė ◽  
Monika Šadauskaitė

There is currently no common or standardized procedure for certification of the energy performance of buildings, as each EU Member State takes into account the specificities of its own construction sector when implementing the provisions of Directive 2010/31/EU. This usually depends on two features: the purpose of the building and the climate. Therefore, the purpose of this paper is to evaluate the influence of the hydropower primary energy factor on assessing the energy performance of buildings. For this purpose, non-renewable primary energy factor values were analyzed regarding actual energy production and consumption data from 19 Lithuanian hydroelectric plants. The results of the studies show that the average value of the non-renewable primary energy factor of hydropower plants is 0.059.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Norhayati Mahyuddin ◽  
Mozhgan Samzadeh ◽  
Suzaini M. Zaid ◽  
Norafida Ab Ghafar

PurposeThis paper aims to raise awareness on how a simple action by the occupant can significantly influence building energy efficiency, cost and CO2 emissions to the environment. Classrooms in schools are the primary energy consumers (45.4%) due to the use of artificial lighting, despite Malaysia's tropical climate being ideal for daylight exploitation. This paper focuses on assessing the workplane daylight distribution quality and quantity in baseline and existing conditions of a typical pre-school classroom in Kuala Lumpur as a model-based exploration strategy towards nearly Zero Energy Buildings.Design/methodology/approachThe adopted method is based on the calculation of average daylight factor (DF), daylight illuminance level (IL) and uniformity ratio (UR) parameters affected by the internal fixed drapes through computational and in situ measurements according to the requirements of the law and respective standards comprising the MS1525:2019, GBI and BREEAM.FindingsThe results show how user behaviour can turn a well-daylit area (Net Lettable Area>90%) into a poor-daylit area (NLA<5%) by sacrificing natural daylight. All the parameters' values were significantly decreased from 10% (UR) up to 88% (ADF). Full dependency on artificial lighting has imposed a total of RM18858.90 and CO2 emissions of 25,362 kg for all pre-schools' classrooms in the country per day.Social implicationsThe paper develops the occupants' awareness on their contribution to climate change and global warming through the information and transparency provided.Originality/valueThe evidence indicates that a simple action by the occupant can significantly influence visual comfort, EE, cost and CO2 emissions to the environment.


Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2979 ◽  
Author(s):  
Javier Rey-Hernández ◽  
Eloy Velasco-Gómez ◽  
Julio San José-Alonso ◽  
Ana Tejero-González ◽  
Sergio González-González ◽  
...  

The building sector is responsible for a substantial part of the energy consumption and corresponding CO2 emissions. The European Union has consequently developed various directives, among which the updated Energy Performance of Buildings Directive 2018/844/EU stands out, aiming at minimizing the energy demand in buildings, improving the energy efficiency of their facilities and integrating renewable energies. The objective of the present study was to develop an analysis on the energy performance, related CO2 emissions and operating costs of the renewable energy technologies implemented within a multipurpose near Zero Energy Building (nZEB). The target building is an existing nZEB called LUCIA, located in Valladolid (Spain). Monitoring data provides the required information on the actual needs for electricity, cooling and heating. It is equipped with solar energy photovoltaic systems, a biomass boiler and a geothermal Earth to Air Heat Exchanger (EAHX) intended for meeting the ventilation thermal loads. All systems studied show favourable performances, but depend significantly on the particular characteristics of the building, the control algorithm and the climate of the location. Hence, design of these strategies for new nZEBs must consider all these factors. The combined use of the PhotoVoltaic PV System, the biomass and the EAHX reduces the CO2 emissions up to 123 to 170 tons/year in comparison with other fuels, entailing economic savings from the system operation of up to 43,000–50,000 €/year.


Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4625 ◽  
Author(s):  
Anna Życzyńska ◽  
Zbigniew Suchorab ◽  
Dariusz Majerek

The paper presented the analysis of heat consumption for heating in multi-family residential buildings before and after thermal retrofitting. The analysis involved four groups of buildings, i.e., 43 buildings in total, located in various localities, belonging to one weather station. The predicted level of energy savings resulting from thermal retrofitting was achieved from the energy audits. The actual heat consumption, following the calculation into so-called external standard conditions, was obtained based on the readouts from heat-meters. For each building, the values of heat consumption over the periods of 6–10 years were read. The performance measurements involved the periods before, during, and after thermal retrofitting. The following statistical tests were used for data analysis: Wilcoxon–Mann–Whitney, Shapiro–Wilk, Bartlett, ANOVA, Kruskal–Wallis, Dunn and Holm post-hoc. The performed analyses showed that the mean value of energy savings predicted by audits reached 38.5% when the real mean value of savings, achieved from heat-meters, equaled 30.3%. The annual energy demand factors for heating were calculated for final energy and non-renewable primary energy factors. It was established that most of the analyzed objects fulfilled the primary energy factor requirements found in the Polish technical and construction regulations, which were valid at the time of investment.


2014 ◽  
Vol 1020 ◽  
pp. 561-565 ◽  
Author(s):  
Rastislav Ingeli ◽  
Katarína Minarovičová ◽  
Miroslav Čekon

Buildings account for 40% of the primary energy use and 24%of the generation of green house gases worldwide. Therefore, a reduction of the specific energy demand of buildings and increased use of renewable energy are important measures of climate change mitigation. On the 18th of May 2010 a recast of the EPBD was approved which further clarifies the intention that buildings shall have a low energy demand. The recast of the EPBD specifies that by the end of 2020 all new buildings shall be “nearly zero-energy buildings”. A nearly zero-energy building is defined as a building with a very high energy performance and very simple shape. The current focusing on the energy efficiency of the building operation may lead to uniform cuboid architecture with heavy insulated building envelopes. The paper deals with the influence of energy concept on architectural elements (and their properties as shape, material, colour, texture etc.)


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